Corethrella (Corethrella) ranapungens Borkent, 2008

Published, First, 2008, The Frog-Biting Midges of the World (Corethrellidae: Diptera), Zootaxa 1804, pp. 1-456 : 160-163

Corethrella (Corethrella) ranapungens Borkent , new species

DIAGNOSIS: Male adult: only extant species of Corethrella in the New World with flagellomeres 4–10 each with dense sensilla trichodea (Fig. 65K), flagellomeres 9–12 each with one sensillum coeloconicum, a distinct midlength wing band (Fig. 64K), thorax dark brown (as in Fig. 54A), halter and scutellum equally dark brown, midfemur dark brown and equal to that of base of hind femur, base of hind tibia darkly pigmented (contrasting with pale apex of hind femur), with apical 0.2–0.3 of hind femur pale (as in Fig. 55A), midfemur without scales, and segments 8 and 9 and base of gonocoxite equally medium brown (Fig. 80D). Female adult: only extant species of Corethrella in the New World with flagellomeres 2 and 3 moderately elongate ( Figs. 31B, C), flagellomeres 9–12 each with one sensillum coeloconicum, thorax dark brown ( Fig. 55A), a distinct midlength wing band with dark scales present on all veins and more basal dark scales only on C, Sc, R and in some, on M (Fig. 71C), halter and scutellum equally dark brown, midfemur thick, dark brown and equal to that of base of hind femur, with apical 0.2–0.3 of hind femur pale, base of hind tibia darkly pigmented (contrasting with pale apex of hind femur) ( Fig. 55A), midfemur without scales.

DESCRIPTION: Male adult. Descriptive statistics: see Tables 2–5. Head: Outline in anterior view laterally elongate (as in Fig. 13A). Two large setae on frons between ventromedial area of ommatida (as in Fig. 16B). Antenna medium brown; pedicel with at least one distinctive, more elongate, stout, dorsal or dorsolat- eral seta; flagellomeres as in Fig. 23K, sensilla coeloconica distributed as in Table 1; flagellomere 13 with well-developed apical bifurcation. Palpus medium brown; segment 3 of nearly constant width. Thorax (as in Fig. 55A): Medium to dark brown, pale sclerites around base of wing. Posterior portion of dorsocentral row with group of about 4 elongate setae. Prescutal suture short, not extending more than half way to dorsocentral row of setae. Anterior anepisternum divided diagonally by sinuous suture, dorsal portion about equal to ventral portion. Ventral portion of posterior anepisternum triangular, uniformly brown, with anterodorsal margin thick. Wing (Fig. 64K): Apex of R 2 basal to apex of M 1. Anterior margin with differently, discretely pigmented scales (indicating anterior margin of midlength band), with midlength band, more basal dark scales only on C, Sc, R and in some, on M, with apical band with dark scales on R 2, R 3, R 4+5, M 1, some specimens on M 2; veins (other than costa and wing margin) with well-developed scales. Halter as dark as scutellum. Legs (as in Fig. 55A): Dark brown, with apical 0.2–0.3 hind femur pale, hind tibia with non-discrete to somewhat discrete, slightly to significantly darker, basal and apical pigmentation. With only slender setae, lacking scales (except for some in patch of whip-like setae on posterior portion of hind tibia). Midleg with thick, subapical setae on each of at least tarsomeres 1–3. Apices of fore-, midleg fifth tarsomeres undivided, with claws slightly subapical to apical (as in Fig. 75F). Claw of foreleg longer than those of mid-, hind leg. Each claw without inner tooth. Anterior claws of each leg without a basal prong. Foreleg claws unequal. Midleg claws equal. Foreleg third tarsomere shorter than fourth tarsomere. Empodia slender. Abdomen (Fig. 80D): Medium to dark brown, with posterior margins of each of tergites 5–7 slightly darker in some. Genitalia (Fig. 95D): Gonocoxite medium to dark brown, gently tapering; anteromedial area with spicules similar in length to those elsewhere on gonocoxite; with well-defined dorsal row of setae, with seta 2 slightly thicker than others, with row restricted to dorsal portion of gonocoxite. With one dorsomedial stout seta, more or less of even thickness for most of length, tapering near apex. Gonostylus (partially extended) straight or gently curved, slender, expanded apically, of more or less equal thickness for entire length, pointed apically; one elongate, slender subbasal seta, situated anteriorly or anteroventrally; apical seta slender, elongate, simple. Aedeagus slender, elongate, tapering gradually to apex, pointed apically, with lateral margins fused at apex.

Female adult. Descriptive statistics: see Tables 6–11. As for male, with following differences. Head: Coronal suture elongate, extending ventrally past ommatida (as in Fig. 16B). Antenna medium to dark brown; with flagellomeres as in Fig. 31B, C, sensilla coeloconica distributed as in Table 1. Clypeus ( Fig. 18Z) squarish. Mandible with small, pointed teeth. Palpus as in Fig. 35F. Wing (Fig. 71C). Legs: Claws of each leg equal to those of others; equal on each leg, simple (without inner teeth). Abdomen: Medium to dark brown with segments 8–9 darker brown in those with rest of abdomen medium brown. Cercus dark brown.

Pupa. Mostly undescribed. Thorax: Scutum, metathorax each with spherical sensory pit (as in Fig. 100A). Respiratory organ (Fig. 103D): Tubular. Abdomen (Fig. 110A): Segments 3–7 somewhat expanded laterally. Paddle only moderately elongate; apicodorsal thick spine articulating; apicoventral seta longer than thick spine.

Larva. Undescribed.

Egg. With sculpturing, similar to that described by McKeever and French (1991b) ( Fig. 5A).

DISTRIBUTION AND BIONOMICS: Corethrella ranapungens is known from southern Mexico, Costa Rica, Panama, Guyana, French Guiana, Trinidad and Tobago and Brazil (Fig. 137) at altitudes ranging from 3–1800 m. The specimens from high altitudes may represent a separate species (see below). Specimens have been collected using light, Malaise and frog-call traps and a few specimens from Trinidad and Tobago were reared from a swamp margin. Female C. ranapungens were often one of the most common species in frogcall traps in Costa Rica (using Hyla gratiosa calls). For example, at Hitoy Cerere National Park, on October 11, 2003, female adult C. ranapungens made up 43% of a total of 754 Corethrella females collected that night. Fourteen females of this species were collected from a calling male of Hyla rosenbergi Boulenger at Gamboa, Panama (Stan Rand, pers. comm.), with no other species collected during that time (USNM; 12 nonparatypes on pins). One female was collected feeding on the nostril area of Dendropsophus ebraccatus (Cope) (Ximena Bernal, pers. comm.) from that same site. Frog-call traps in Panama run by X. Bernal, using calls of Physalaemus pustulosus , Dendropsophus microcephalus , and Hyla gratiosa captured female C. ranapungens and G. Bourne collected this species in Guyana with the taped calls of Bufo typhonius and Scinax ruber .

Adults were reared from eggs laid by a female collected with a frog-call trap at 5 km NE Tárcoles, Costa Rica (Carara National Park). Eggs floated individually at the surface. Hatching larvae escaped the egg shell through one end which was partially detached. Two first instars were placed in a thin film of water in a petri dish to determine if they used their prolegs to transport themselves but they merely lashed about in typical culicid fashion. Larvae anchored themselves with both pairs of strong setae at the apex of the siphon and were nearly always at the bottom of the petri dish. Compared to the larvae of C. quadrivittata , they were much more lethargic. They fed in the typical manner described in the generic synopsis.

The pupae of C. ranapungens were mostly submerged and could slowly arched their abdomens. These submerged pupae failed to emerge as adults unless placed on wet paper.

The specimens from the Belkin “Mosquitoes of Middle America” project are identified in Table 12.

TAXONOMIC DISCUSSION: Males and females were associated through the shared presence of a common pigmentation pattern and were collected together in Costa Rica and French Guiana.

Females of C. ranapungens are strikingly variable in shape of the clypeus, relative sizes of palpal segments, relative lengths of flagellomeres 1–3 ( Figs. 31B, C), and extent of wing pigmentation. I suspect that more than one species may be present, especially from higher altitudes in Costa Rica, Trinidad and Tobago and among specimens from French Guiana. However, I was unable to find consistent differences allowing for the recognition of two or more morphotypes. The great altitudinal distribution of this species from 3 to 1800 meters (in Costa Rica) further suggests that more than one species may be present in the material at hand, although there are a few other species of Corethrella with such broad altitudinal range. One female from Trinidad and Tobago (Nariva, “Bush Bush Forest “, Trinidad and Tobago, 1 m, 16-III-1964) had quite short flagellomeres 2 and 3, approximating the very short condition in C. curta ( Fig. 31D) but the specimen was somewhat teneral, suggesting that this may, in part, be an artifact.

Two males from Tuparro National Park, 140 m, Colombia collected 19–29-VI-2000 and 29-VI–15-VII- 2000 respectively (CNCI), keyed to C. ranapungens but have an apically broad aedeagus that tapers only at its very apex. They likely represent an undescribed species but were identified too late for inclusion here.

One male adult from Trinidad and Tobago had two associated larval and two pupal exuviae. Although it is obvious that only one pair truly belongs to the adult male, I consider all paratypes because the exuviae are very similar and likely conspecific .

This species was referred to as species 1 in Bernal et al. (2006).

TYPES: Holotype, male adult on microscope slide, labeled " HOLOTYPE Corethrella ranapungens Borkent ”, “ 5 km NE Tárcoles, C.R., 2-IX-1993, A. Borkent, CD1567” (CNCI). Allotype, female adult on microscope slide, labeled as for holotype ( CNCI) . Paratypes: 2 ♀, Tapachula, Chiapas, Mexico, 20-IX-1944 ( USNM) ; 1 ♂, Colejio Superior de Agricultura Tropical , Cardenas, Tabasco, Mexico, 20 m, 15-VII-1970 ( USNM) ; 1 ♀ -, Heliconias trail, Alberque Heliconias, Upala, Costa Rica, 700 m, 17-VII–17-VIII-2000 ( INBC) ; 1 ♂, 15 ♀ (one with pupal exuviae) from type locality ( CNCI) ; 6 ♀, type locality but 17-VIII-1993 ( CNCI) ; 2 ♀, type locality but 20-VII-1993 ( CNCI; BPBM) ; 5 ♀, 2 km NE Tárcoles , Costa Rica, 100 m, 26- VII-1993 ( CNCI) ; 7 ♀, Tárcoles , Costa Rica, 2 m, 11-XI-1993 (6 ♀ CNCI; 1 ♀ ANIC) ; 2 ♀, from previous locality but 28-IX-1993 ( CNCI) ; 5 ♀, Manuel Antonio National Park , Costa Rica, 3 m, 17-XI-1993 (3 ♀ CNCI; 2 ♀ ANIC) ; 1 ♀, 5 km NW Rincón, Osa Peninsula , Costa Rica, 10-VIII-2001 ( CNCI) ; 3 ♀, Orilla de E Agujas, Golfo R.F., Puntarenas, Costa Rica, 250–350 m, 30-VI–1-VII-2000 ( INBC) ; 2 ♀, Estación Los Planes, Corcovado National Park , Costa Rica, 180 m, 23–24-VII-2002 ( INBC) ; 1 ♀, Tapantí National Park , Costa Rica, 1800 m, XII-1996 ( INBC) ; 1 ♀, from previous locality but I-1999 ( INBC) ; 1 ♀, between Porras and Villegas Rivers , Costado Torre del I.C.E., Sector La Represa, Costa Rica, 1800 m, III-1997 ( INBC) ; 9 ♀, nr administration building (9°58.52'N, 83°27.15'W), Barbilla National Park , 500 m, 10-II-2006 ( CNCI) ; 13 ♀, La Selva Biological Station , Puerto Viejo de la Sarapiqui, Heredia, Costa Rica, 40 m, 1-III-2004 ( CNCI) ; 9 ♀, Hitoy Cerere Biological Reserve , nr. administation building (9°40.30'N, 83°01.20'W), Costa Rica, 100 m, 11- X-2003 ( CNCI) ; 3 ♀, Gamboa, Panama, 27 m, 21-VII-2002 ( USNM) ; 4 ♀, from previous locality, 9°07.0'N, 79°41.9'W, but 25-VI-2003 ( CNCI) ; 2 ♀, from previous locality but 20-VII-2003 ( CNCI) ; 1 ♀, from previous locality but 16-VIII-2003 ( CNCI) ; 1 ♀, from previous locality but 17-VIII-2003 ( CNCI) ; 2 ♀, from previous locality but 18-VIII-2003 ( CNCI) ; 1 ♀, Barro Colorado Island , Panama, VII-1967 ( USNM) ; 1 ♀, Patino Point, Darien Pr., Panama, 2-VIII-1952 ( USNM) ; 11 ♀, CEIBA Biological Center , 06°29 N, 58° 13 W, Guyana, 20- III-2006 ( CNCI) ; 3 ♀, Dubulay Ranch, Guyana, 05°,40’56’’ N, 57°, 51’29’’ W, 14-III-2006 ( CNCI) ; 2 ♂, 5 km SE Cayenne , Guyane, French Guiana, 5 m, 3-4-1965 ( USNM) ; 1 ♀, from previous locality but 31-I-1-II-1965 ( USNM) ; 1 ♀, from previous locality but 2–3-II-1965 ( USNM) ; 1 ♂, 1 ♀, 0.5 km N Lac du Rorota, Remire , Guyane, French Guiana, 100 m, 6–7-II-1965 ( USNM) ; 12 ♀, 24 km SW Cayenne , Guyane, French Guiana, 5 m, 1–2-II-1965 ( USNM) ; 1 ♂ with pupal exuviae, 1 ♂ with 2 pupal and 2 larval exuviae, 1 ♀ with pupal exuviae, Nariva, “ Bush Bush Forest “, Trinidad and Tobago, 1 m, 16-III-1964 ( USNM) ; 1 ♀ from previous locality but 2–3-XI-1965 ( USNM) ; 2 ♀, IPEAN, Belem, Para, Brazil, 30 m, 8–9-IX-1970 ( USNM) ; 1 ♀, Guana River Pump Stations, Instituto de Pesquisas e Experimentacao Agropecuarias do Norte, nr Belem, Para, Brazil, 30 m, 29–30-IX-1970 ( USNM) .

DERIVATION OF SPECIFIC EPITHET: The name ranapungens (frog biter) refers to the frog-biting habit of the adult female of this species.